Data transfer object

Last updated

In the field of programming a data transfer object (DTO [1] [2] ) is an object that carries data between processes. The motivation for its use is that communication between processes is usually done resorting to remote interfaces (e.g., web services), where each call is an expensive operation. [2] Because the majority of the cost of each call is related to the round-trip time between the client and the server, one way of reducing the number of calls is to use an object (the DTO) that aggregates the data that would have been transferred by the several calls, but that is served by one call only. [2]

Contents

The difference between data transfer objects and business objects or data access objects is that a DTO does not have any behavior except for storage, retrieval, serialization and deserialization of its own data (mutators, accessors, serializers and parsers). In other words, DTOs are simple objects that should not contain any business logic but may contain serialization and deserialization mechanisms for transferring data over the wire. [1]

This pattern is often incorrectly used outside of remote interfaces. This has triggered a response from its author [3] where he reiterates that the whole purpose of DTOs is to shift data in expensive remote calls.

Terminology

A value object is not a DTO. The two terms have been conflated by Sun/Java community in the past. [2]

For model-view-viewmodel pattern, the data transfer object can be referred to as the viewmodel. [4]

Related Research Articles

In software engineering, multitier architecture is a client–server architecture in which presentation, application processing and data management functions are physically separated. The most widespread use of multitier architecture is the three-tier architecture.

In distributed computing, a remote procedure call (RPC) is when a computer program causes a procedure (subroutine) to execute in a different address space, which is written as if it were a normal (local) procedure call, without the programmer explicitly writing the details for the remote interaction. That is, the programmer writes essentially the same code whether the subroutine is local to the executing program, or remote. This is a form of client–server interaction, typically implemented via a request–response message passing system. In the object-oriented programming paradigm, RPCs are represented by remote method invocation (RMI). The RPC model implies a level of location transparency, namely that calling procedures are largely the same whether they are local or remote, but usually, they are not identical, so local calls can be distinguished from remote calls. Remote calls are usually orders of magnitude slower and less reliable than local calls, so distinguishing them is important.

In computing, serialization is the process of translating a data structure or object state into a format that can be stored or transmitted and reconstructed later. When the resulting series of bits is reread according to the serialization format, it can be used to create a semantically identical clone of the original object. For many complex objects, such as those that make extensive use of references, this process is not straightforward. Serialization of objects does not include any of their associated methods with which they were previously linked.

VBScript is a deprecated programming language for scripting on Microsoft Windows using Component Object Model (COM) based on classic Visual Basic and Active Scripting.

The Common Object Request Broker Architecture (CORBA) is a standard defined by the Object Management Group (OMG) designed to facilitate the communication of systems that are deployed on diverse platforms. CORBA enables collaboration between systems on different operating systems, programming languages, and computing hardware. CORBA uses an object-oriented model although the systems that use the CORBA do not have to be object-oriented. CORBA is an example of the distributed object paradigm.

<span class="mw-page-title-main">Interface description language</span> Computer language used to describe a software components interface

An interface description language or interface definition language (IDL) is a generic term for a language that lets a program or object written in one language communicate with another program written in an unknown language. IDLs are usually used to describe data types and interfaces in a language-independent way, for example, between those written in C++ and those written in Java.

<span class="mw-page-title-main">Model–view–controller</span> Software design pattern

Model–view–controller (MVC) is a software design pattern commonly used for developing user interfaces that divides the related program logic into three interconnected elements. These elements are:

In distributed computing, an object request broker (ORB) is a concept of a middleware, which allows program calls to be made from one computer to another via a computer network, providing location transparency through remote procedure calls. ORBs promote interoperability of distributed object systems, enabling such systems to be built by piecing together objects from different vendors, while different parts communicate with each other via the ORB. Common Object Request Broker Architecture standardizes the way ORB may be implemented.

Ajax is a set of web development techniques that uses various web technologies on the client-side to create asynchronous web applications. With Ajax, web applications can send and retrieve data from a server asynchronously without interfering with the display and behaviour of the existing page. By decoupling the data interchange layer from the presentation layer, Ajax allows web pages and, by extension, web applications, to change content dynamically without the need to reload the entire page. In practice, modern implementations commonly utilize JSON instead of XML.

In software engineering, a plain old Java object (POJO) is an ordinary Java object, not bound by any special restriction. The term was coined by Martin Fowler, Rebecca Parsons and Josh MacKenzie in September 2000:

"We wondered why people were so against using regular objects in their systems and concluded that it was because simple objects lacked a fancy name. So we gave them one, and it's caught on very nicely."

A web framework (WF) or web application framework (WAF) is a software framework that is designed to support the development of web applications including web services, web resources, and web APIs. Web frameworks provide a standard way to build and deploy web applications on the World Wide Web. Web frameworks aim to automate the overhead associated with common activities performed in web development. For example, many web frameworks provide libraries for database access, templating frameworks, and session management, and they often promote code reuse. Although they often target development of dynamic web sites, they are also applicable to static websites.

The Windows Communication Foundation (WCF), previously known as Indigo, is a free and open-source runtime and a set of APIs in the .NET Framework for building connected, service-oriented applications.

Remote scripting is a technology which allows scripts and programs that are running inside a browser to exchange information with a server. The local scripts can invoke scripts on the remote side and process the returned information.

In software engineering, a plain old CLR object, or plain old class object (POCO) is a simple object created in the .NET Common Language Runtime (CLR) that is unencumbered by inheritance or attributes. This is often used in opposition to the complex or specialized objects that object-relational mapping frameworks often require. In essence, a POCO does not have any dependency on an external framework.

In Microsoft Windows applications programming, OLE Automation is an inter-process communication mechanism created by Microsoft. It is based on a subset of Component Object Model (COM) that was intended for use by scripting languages – originally Visual Basic – but now is used by several languages on Windows. All automation objects are required to implement the IDispatch interface. It provides an infrastructure whereby applications called automation controllers can access and manipulate shared automation objects that are exported by other applications. It supersedes Dynamic Data Exchange (DDE), an older mechanism for applications to control one another. As with DDE, in OLE Automation the automation controller is the "client" and the application exporting the automation objects is the "server".

.NET Remoting is a Microsoft application programming interface (API) for interprocess communication released in 2002 with the 1.0 version of .NET Framework. It is one in a series of Microsoft technologies that began in 1990 with the first version of Object Linking and Embedding (OLE) for 16-bit Windows. Intermediate steps in the development of these technologies were Component Object Model (COM) released in 1993 and updated in 1995 as COM-95, Distributed Component Object Model (DCOM), released in 1997, and COM+ with its Microsoft Transaction Server (MTS), released in 2000. It is now superseded by Windows Communication Foundation (WCF), which is part of the .NET Framework 3.0.

In computer science, marshalling or marshaling is the process of transforming the memory representation of an object into a data format suitable for storage or transmission, especially between different runtimes. It is typically used when data must be moved between different parts of a computer program or from one program to another.

<span class="mw-page-title-main">Model–view–presenter</span> Software design pattern

Model–view–presenter (MVP) is a derivation of the model–view–controller (MVC) architectural pattern, and is used mostly for building user interfaces.

Component Object Model (COM) is a binary-interface standard for software components introduced by Microsoft in 1993. It is used to enable inter-process communication (IPC) object creation in a large range of programming languages. COM is the basis for several other Microsoft technologies and frameworks, including OLE, OLE Automation, Browser Helper Object, ActiveX, COM+, DCOM, the Windows shell, DirectX, UMDF and Windows Runtime.

Model–view–viewmodel (MVVM) is an architectural pattern in computer software that facilitates the separation of the development of a graphical user interface —be it via a markup language or GUI code—from the development of the business logic or back-end logic such that the view is not dependent upon any specific model platform.

References

  1. 1 2 MSDN (2010). Data Transfer Object. Microsoft MSDN Library. Retrieved from https://msdn.microsoft.com/en-us/library/ms978717.aspx.
  2. 1 2 3 4 Fowler, Martin (2010). Data Transfer Object. Patterns of Enterprise Application Architecture. Retrieved from http://martinfowler.com/eaaCatalog/dataTransferObject.html.
  3. LocalDTO. Retrieved from http://martinfowler.com/bliki/LocalDTO.html.
  4. Microsoft Learn (3 January 2024). "Tutorial: Create a web API with ASP.NET Core".